Shubnikov-de Haas oscillations in the anomalous Hall conductivity of Chern insulators

TL;DR

This paper demonstrates that the anomalous Hall conductivity in Chern insulators exhibits Shubnikov-de Haas oscillations under high magnetic fields, revealing insights into topological electronic transport properties.

Contribution

It provides a detailed numerical and analytical study of SdH oscillations in Chern insulators, extending understanding beyond linear Dirac models.

Findings

Visible SdH oscillations in Hall conductivity at low temperature

Modulation of flux accumulation due to Haldane term causes oscillations

Dependence of spectral shifts on magnetic field reversal and topological gap

Abstract

The Haldane model on a honeycomb lattice is a paradigmatic example of a system featuring quantized Hall conductivity in the absence of an external magnetic field, that is, a quantum anomalous Hall effect. Recent theoretical work predicted that the anomalous Hall conductivity of massive Dirac fermions can display Shubnikov-de Haas (SdH) oscillations, which could be observed in topological insulators and honeycomb layers with strong spin--orbit coupling. Here, we investigate the electronic transport properties of Chern insulators subject to high magnetic fields by means of accurate spectral expansions of lattice Green's functions. We find that the anomalous component of the Hall conductivity displays visible SdH oscillations at low temperature. \textcolor{black}{The effect is shown to result from the modulation of the next-nearest neighbour flux accumulation due to the Haldane term,} which removes the electron--hole symmetry from the Landau spectrum. To support our numerical findings, we derive a long-wavelength description beyond the linear ('Dirac cone') approximation. Finally, we discuss the dependence of the energy spectra shift for reversed magnetic fields with the topological gap and the lattice bandwidth.